Alter table to apply partitioning by key in mysql - mysql

Question

I have a table with million of rows and the frequency of growth will probably increase in future, so far about 4.3 million rows are added in a month, causing the database to slow down. I have already applied indexing but it's not really optimizing the speed. Is applying Partitioning to such data favorable?
Also how can I apply partitioning on a table with million of rows? I know it will look something like this
ALTER TABLE gpsloggs
PARTITION BY KEY(DeviceCode)
PARTITIONS 10;
The problem is I was Partitioning on DeviceCode which is not a primary key so partitioning isn't permissible.
DROP TABLE IF EXISTS `gpslogss`;
CREATE TABLE `gpslogss` (
`Id` int(11) NOT NULL AUTO_INCREMENT,
`DeviceCode` varchar(255) DEFAULT NULL,
`Latitude` varchar(255) DEFAULT NULL,
`Longitude` varchar(255) DEFAULT NULL,
`Speed` double DEFAULT NULL,
`rowStamp` datetime DEFAULT NULL,
`Date` varchar(255) DEFAULT NULL,
`Time` varchar(255) DEFAULT NULL,
`AlarmCode` int(11) DEFAULT NULL,
PRIMARY KEY `Id` (`Id`) USING BTREE,
KEY `DeviceCode` (`DeviceCode`) USING BTREE
);
So I altered the table and made the table in a new database with 0 records this way and it worked fine
DROP TABLE IF EXISTS `gpslogss`;
CREATE TABLE `gpslogss` (
`Id` int(11) NOT NULL AUTO_INCREMENT,
`DeviceCode` varchar(255) DEFAULT NULL,
`Latitude` varchar(255) DEFAULT NULL,
`Longitude` varchar(255) DEFAULT NULL,
`Speed` double DEFAULT NULL,
`rowStamp` datetime DEFAULT NULL,
`Date` varchar(255) DEFAULT NULL,
`Time` varchar(255) DEFAULT NULL,
`AlarmCode` int(11) DEFAULT NULL,
KEY `Id` (`Id`) USING BTREE,
KEY `DeviceCode` (`DeviceCode`) USING BTREE
);
PARTITION BY KEY(DeviceCode)
PARTITIONS 10;
How should I render the code so that I can apply partitioning to the table with million of rows? How should I drop keys and alter the table to apply partitioning without damaging data?

Answer 1

Short answer: Don't.
Long answer: PARTITION BY KEY does not provide any performance benefit (that I know of). And why else use PARTITION?
Other notes:
You should use InnoDB for virtually all tables.
InnoDB tables should have an explicit PRIMARY KEY.
There is a DATETIME datatype; don't use VARCHAR for date or time, and don't split them.
latitude and longitude are numeric; don't use VARCHAR. FLOAT is a likely candidate (precise enough to differentiate vehicles, but not people).
Your real question is about speed. Let's see the slow SELECTs and work backward from them. Adding PARTITIONing is rarely a solution to performance.